Arogenate dehydratase | |||||||||
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Identifiers | |||||||||
EC no. | 4.2.1.91 | ||||||||
CAS no. | 76600-70-9 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
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Arogenate dehydratase (ADT) (EC 4.2.1.91) is an enzyme that catalyzes the chemical reaction
Certain forms of the protein have the potential to catalyze a second reaction, [1]
This enzyme participates in phenylalanine, tyrosine, and tryptophan biosynthesis (an example structure is shown to the right. [2]
This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is L-arogenate hydro-lyase (decarboxylating; L-phenylalanine-forming). Other names in common use include:
The carboxyl and hydroxide groups (shown in red) attached to the 2,5-cyclohexene ring are eliminated from L-arogenate, leaving as carbon dioxide and water. The 2,5-cyclohexene ring becomes a phenyl ring, and L-phenylalanine is formed.
Certain forms of ADT have been shown to exhibit some prephenate dehydratase (PDT) activity in addition to the standard ADT activity described above. [1] Known as cyclohexadienyl dehydratases or carbocyclohexadienyl dehydratases (listed above), [1] these forms of the enzyme catalyze the same type of reaction (a decarboxylation and a dehydration) on prephenate. The carboxyl and hydroxide groups (in red) attached to the 2,5-cyclohexene ring are removed, leaving phenylpyruvate.
ADT catalyzes a reaction categorized by two major changes in the structure of the substrate, these being a decarboxylation and a dehydration; the enzyme removes a carboxyl group and a water molecule (respectively). [1] Both potential products of this reaction (L-arogenate and phenylpyruvate) occur at or near the end of the biosynthetic pathway. Total synthesis of L-arogenate has been reported. [3] [4]
The structure of arogenate dehydratases are described as having, for the most part, three major sections. ADTs contain an N-terminal transit peptide, a PDT-like domain, and an ACT (Aspartokinase, chorismate mutase, TyrA) domain. [5]
Homologues for ADT have been isolated in Arabidopsis thaliana (rabbit-ear cress), [5] Nicotiana sylvestris (tobacco), [6] Spinacia oleracea (spinach), [6] Petunia hybrida, [7] Sorghum bicolor , [8] Oryza sativa , [9] and Pinus pinaster [10] which are all considered higher-order plants. Erwinia herbicola [11] and Pseudomonas aeruginosa [12] are known to have homologues for cyclohexadienyl dehydratase. Of the plants with ADT homologues, both Arabidopsis thaliana, Petunia hybrida, and Pinus pinaster are known to have paralogues for the gene (six, three, and nine, respectively). [5] [7] [10]
Dehydratases are a group of lyase enzymes that form double and triple bonds in a substrate through the removal of water. They can be found in many places including the mitochondria, peroxisome and cytosol. There are more than 150 different dehydratase enzymes that are classified into four groups. Dehydratases can act on hydroxyacyl-CoA with or without cofactors, and some have a metal and non-metal cluster act as their active site.
Shikimic acid, more commonly known as its anionic form shikimate, is a cyclohexene, a cyclitol and a cyclohexanecarboxylic acid. It is an important biochemical metabolite in plants and microorganisms. Its name comes from the Japanese flower shikimi, from which it was first isolated in 1885 by Johan Fredrik Eykman. The elucidation of its structure was made nearly 50 years later.
In enzymology, an arogenate dehydrogenase (EC 1.3.1.43) is an enzyme that catalyzes the chemical reaction
Prephenate dehydrogenase is an enzyme found in the shikimate pathway, and helps catalyze the reaction from prephenate to tyrosine.
Cystathionine beta-lyase, also commonly referred to as CBL or β-cystathionase, is an enzyme that primarily catalyzes the following α,β-elimination reaction
The enzyme ornithine cyclodeaminase catalyzes the chemical reaction
The enzyme phenylalanine ammonia lyase (EC 4.3.1.24) catalyzes the conversion of L-phenylalanine to ammonia and trans-cinnamic acid.:
The enzyme phenylpyruvate decarboxylase (EC 4.1.1.43) catalyzes the chemical reaction
The enzyme 2-dehydro-3-deoxy-L-arabinonate dehydratase (EC 4.2.1.43) catalyzes the chemical reaction
The enzyme 3-dehydroquinate dehydratase (EC 4.2.1.10) catalyzes the chemical reaction
The enzyme GDP-mannose 4,6-dehydratase (EC 4.2.1.47) catalyzes the chemical reaction
The enzyme L-arabinonate dehydratase (EC 4.2.1.25) catalyzes the chemical reaction
The enzyme prephenate dehydratase (EC 4.2.1.51) catalyzes the chemical reaction
In enzymology, an aspartate-phenylpyruvate transaminase is an enzyme that catalyzes the chemical reaction
In enzymology, glutamate-prephenate aminotransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a tryptophan-phenylpyruvate transaminase is an enzyme that catalyzes the chemical reaction:
The shikimate pathway is a seven-step metabolic pathway used by bacteria, archaea, fungi, algae, some protozoans, and plants for the biosynthesis of folates and aromatic amino acids. This pathway is not found in mammals.
Phenylalanine N-monooxygenase (EC 1.14.14.40, phenylalanine N-hydroxylase, CYP79A2) is an enzyme with systematic name L-phenylalanine,NADPH:oxygen oxidoreductase (N-hydroxylating). This enzyme catalyses the following chemical reaction
Isochorismate pyruvate lyase is an enzyme responsible for catalyzing part of the pathway involved in the formation of salicylic acid. More specifically, IPL will use isochorismate as a substrate and convert it into salicylate and pyruvate. IPL is a PchB enzyme originating from the pchB gene in Pseudomonas aeruginosa.
Arogenic acid is an intermediate in the biosynthesis of phenylalanine and tyrosine. At physiological pH it exists as its conjugate base arogenate as the acid form is unstable.
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